# The 100 largest companies in the Seine-Maritime department

Tamtam tracks 918 companies headquartered in the Seine-Maritime department. This list ranks the 100 largest by number of employees on LinkedIn, led by Sidel, Matmut and CHU de Rouen. Their median headcount is 314. Half of them were founded in 1986 or later. The most common headquarters are Rouen (28), Le Havre (24) and Saint-Étienne-du-Rouvray (6).

These are the largest companies in the French department of Seine-Maritime, predominantly large organizations. The list features a mix of industries, including manufacturing, finance, education, and public services. Noteworthy examples include Sidel, a packaging equipment provider; Matmut, an insurance group; CHU de Rouen, a major hospital network; and Crédit Agricole Normandie-Seine, a regional bank.

A significant portion of these large employers are public or quasi-public institutions, such as CHU de Rouen, Université de Rouen, and DEPARTEMENT DE LA SEINE-MARITIME. The presence of multiple higher education institutions like Université de Rouen and EM Normandie Business School, alongside major public service providers, indicates a strong public sector employment base in the region.

🇫🇷 Seine-Maritime · 100 companies · Updated Nov 11, 2026

| # | Company | Industry | Headquarters | Employees | Founded |
|---|---|---|---|---|---|
| 1 | [Sidel](https://www.tamtam.ai/c/sidel) (sidel.com)<br>Provides equipment, services for packaging beverages, food, home and personal care products in various materials, focusing on customer needs and performance. | Machinery Manufacturing | 🇫🇷 Octeville-sur-Mer | 6,370 | 1965 |
| 2 | [Matmut](https://www.tamtam.ai/c/matmut) (matmut.fr)<br>Provides diverse insurance products, including health and life, to millions of members, emphasizing sustainability, social responsibility, and community well-being in France. | Insurance | 🇫🇷 Rouen | 4,244 | 1961 |
| 3 | [CHU de Rouen](https://www.tamtam.ai/c/chu-de-rouen) (chu-rouen.fr)<br>Large hospital network providing patient care, medical education, and research, supporting regional healthcare and training future health professionals. | Hospitals and Health Care | 🇫🇷 Rouen | 3,823 |  |
| 4 | [Université de Rouen](https://www.tamtam.ai/c/universite-de-rouen) (univ-rouen.fr)<br>Offers education in law, economics, management, humanities, health, sports, sciences, and technology disciplines. | Higher Education | 🇫🇷 Mont-Saint-Aignan | 3,200 | 1966 |
| 5 | [Crédit Agricole Normandie-Seine](https://www.tamtam.ai/c/credit-agricole-normandie-seine) (ca-normandie-seine.fr)<br>Regional bank with 130 branches and online services for individuals, professionals, farmers, businesses, and public communities in Eure and Seine-Maritime. | Banking | 🇫🇷 Bois-Guillaume | 1,566 |  |
| 6 | [DEPARTEMENT DE LA SEINE-MARITIME](https://www.tamtam.ai/c/departement-de-la-seine-maritime) (seinemaritime.fr)<br>Provides essential social services, manages departmental roads, supports local communities, and promotes education, culture, economic development, and tourism in the region. | Government Administration | 🇫🇷 Rouen | 1,450 |  |
| 7 | [Caisse d'Epargne Normandie](https://www.tamtam.ai/c/caisse-d-epargne-normandie) (caisse-epargne.fr)<br>Regional bank serving individuals, professionals, businesses, and local authorities with tailored financial advice and community project support in Normandy. | Banking | 🇫🇷 Bois-Guillaume | 1,402 | 2008 |
| 8 | [EM Normandie Business School](https://www.tamtam.ai/c/em-normandie-business-school) (em-normandie.com)<br>Established in 1871, this institution is a leading French business school accredited by AMBA, AACSB, and EQUIS It offers management education to students and professionals worldwide | Higher Education | 🇫🇷 Le Havre | 1,196 | 1871 |
| 9 | [Université Le Havre Normandie](https://www.tamtam.ai/c/universite-le-havre-normandie) (univ-lehavre.fr)<br>Educates seven thousand students through specialized departments in international affairs, logistics, engineering, humanities, and sciences focused on human and professional development. | Higher Education | 🇫🇷 Le Havre | 1,042 | 1984 |
| 10 | [FOURE LAGADEC](https://www.tamtam.ai/c/foure-lagadec) (fourelagadec.com)<br>FOURE LAGADEC offers complete service solutions for industries, specializing in boiler production and industrial maintenance with a focus on quality, safety, and the environment | Manufacturing | 🇫🇷 Le Havre | 1,003 | 1922 |
| 11 | [Ville du Havre](https://www.tamtam.ai/c/ville-du-havre) (linktr.ee)<br>local government managing urban planning, environment, port activities, culture, history, tourism, economy, education, sports, and public events | Government Administration | 🇫🇷 Le Havre | 902 |  |
| 12 | [Groupe Hospitalier du Havre - GHH](https://www.tamtam.ai/c/groupe-hospitalier-du-havre-ghh) (ch-havre.fr)<br>Leading healthcare provider, comprehensive care, advanced medical technology, collaboration with other hospitals, diverse medical professions, round-the-clock technical platform. | Hospitals and Health Care | 🇫🇷 Montivilliers | 893 | 1669 |
| 13 | [HAROPA PORT](https://www.tamtam.ai/c/haropa-port) (haropaport.com)<br>Manages a major French river-maritime port network, connecting international shipping with a vast hinterland, handling significant maritime and river traffic. | Transportation, Logistics, Supply Chain and Storage | 🇫🇷 Le Havre | 892 | 2021 |
| 14 | [LASSARAT](https://www.tamtam.ai/c/lassarat) (lassarat.com)<br>A long-standing group specializing in surface treatment and industrial coatings, focused on innovation and customer satisfaction in various sectors worldwide | Oil and Gas | 🇫🇷 Le Havre | 888 | 1946 |
| 15 | [Métropole Rouen Normandie](https://www.tamtam.ai/c/metropole-rouen-normandie) (metropole-rouen-normandie.fr)<br>Manages 71 communes, providing essential services like water, transport, waste, promoting local development, tourism, and actively addressing climate change. | Government Administration | 🇫🇷 Rouen | 886 | 2015 |
| 16 | [SEAFRIGO](https://www.tamtam.ai/c/seafrigo) (seafrigo.com)<br>Global food logistics specialist, managing temperature-controlled supply chains for food, wine, spirits, frozen, fresh products, and general cargo. | Transportation, Logistics, Supply Chain and Storage | 🇫🇷 Le Havre | 856 | 1976 |
| 17 | [CERP ROUEN](https://www.tamtam.ai/c/cerp-rouen) (astera.coop)<br>pharmacy cooperative providing distribution services, technological innovation integration, and reliable, high-quality support for pharmacists' development and needs | Wholesale Drugs and Sundries | 🇫🇷 Rouen | 745 | 1919 |
| 18 | [SPB Group](https://www.tamtam.ai/c/spb-group) (spb.eu)<br>SPB Group designs and manages insurance and assistance offers for daily products and services, specializing in electronic device repair and recycling | Insurance | 🇫🇷 Le Havre | 727 | 1965 |
| 19 | [CRAM](https://www.tamtam.ai/c/cram) (cram.fr)<br>Specializes in energy-efficient thermal and climate system management, maintenance, and innovative solutions focused on economic and ecological performance contracts. | Environmental Services | 🇫🇷 Le Havre | 717 | 1958 |
| 20 | [District scolaire francophone Sud](https://www.tamtam.ai/c/district-scolaire-francophone-sud) (francophonesud.nbed.nb.ca)<br>A French school district in New Brunswick with over 17,000 students in 38 schools, focusing on academic success, Acadian identity, and overall well-being of students and staff | Education | 🇫🇷 Dieppe | 662 |  |
| 21 | [SDIS 76 - Sapeurs-pompiers de la Seine-Maritime](https://www.tamtam.ai/c/sdis-76-sapeurs-pompiers-de-la-seine-maritime) (sdis76.fr)<br>Departmental organization managing emergency services, including fire fighting, victim rescue, risk prevention, and specialized interventions in hazardous environments. | Public Safety | 🇫🇷 Yvetot | 657 |  |
| 22 | [IDEFHI](https://www.tamtam.ai/c/idefhi) (idefhi.fr)<br>A public institution focused on child protection and disability services in Seine-Maritime, offering support for children, adolescents, and adults with disabilities | Community Services | 🇫🇷 Canteleu | 648 | 2008 |
| 23 | [Espace Culturel E.Leclerc](https://www.tamtam.ai/c/espace-culturel-e-leclerc) (e.leclerc)<br>This company operates cultural spaces that offer a variety of products and services to customers | Retail | 🇫🇷 Canteleu | 631 |  |
| 24 | [Groupe LHOTELLIER](https://www.tamtam.ai/c/groupe-lhotellier) (lhotellier.fr)<br>A century-old independent family group specializing in construction, public works, and environmental services, with a strong focus on local development and sustainability | Construction | 🇫🇷 Blangy-sur-Bresle | 608 | 1919 |
| 25 | [Ville de Rouen](https://www.tamtam.ai/c/ville-de-rouen) (rouen.fr)<br>Leading urban center in Normandy, Rouen offers a vibrant cultural scene and diverse activities Committed to quality of life, innovation and community engagement | Government Administration | 🇫🇷 Rouen | 597 |  |
| 26 | [Helvetia Insurance France](https://www.tamtam.ai/c/helvetia-insurance-france) (helvetia.com)<br>Specializes in enterprise risk, marine, and transport insurance for various sectors including construction, automotive fleets, art, and international programs. | Insurance | 🇫🇷 Le Havre | 588 | 1921 |
| 27 | [Carsat Normandie](https://www.tamtam.ai/c/carsat-normandie) (carsat-normandie.fr)<br>Provides retirement, social action, and occupational health services. Manages substantial retirement payments, social support, and workplace prevention across the region. | Government Administration | 🇫🇷 Rouen | 552 |  |
| 28 | [Le Havre Seine Métropole](https://www.tamtam.ai/c/le-havre-seine-metropole) (lehavreseinemetropole.fr)<br>This Metropolis aims for excellence through innovation in economy, society, and environment. It focuses on green and blue economy, higher education, and tourism, serving its 275,000 inhabitants. | Government Administration | 🇫🇷 Le Havre | 527 | 2019 |
| 29 | [Ceacom](https://www.tamtam.ai/c/ceacom) (normandie.ceacom.fr)<br>A customer relationship management company based in Le Havre, offering advisory and service jobs, actively involved in professional insertion networks and local events | Business Consulting and Services | 🇫🇷 Le Havre | 521 | 2006 |
| 30 | [INSA Rouen Normandie](https://www.tamtam.ai/c/insa-rouen-normandie) (insa-rouen.fr)<br>Leading engineering institution providing 9 engineering programs, conducting research across 9 laboratories, and promoting scientific culture, focusing on risk management. | Higher Education | 🇫🇷 Saint-Étienne-du-Rouvray | 511 |  |
| 31 | [Saipol](https://www.tamtam.ai/c/saipol) (saipol.com)<br>A French agri-food company specializing in processing oilseeds into oils, animal feed, renewable transport fuels, and vegetable glycerin | Food and Beverage Manufacturing | 🇫🇷 Grand-Couronne | 493 |  |
| 32 | [Habitat 76](https://www.tamtam.ai/c/habitat-76) (habitat76.fr)<br>Manages over 28,000 social housing units across 190 municipalities, focusing on access, maintenance, and eco-efficient solutions for sustainable living. | Real Estate | 🇫🇷 Rouen | 469 | 1919 |
| 33 | [Education et Formation](https://www.tamtam.ai/c/education-et-formation) (educationetformation.fr)<br>Leading association in developing basic and professional training, combatting illiteracy, and promoting inclusion in society | Professional Training and Coaching | 🇫🇷 Rouen | 461 | 1972 |
| 34 | [Cerfrance Seine Normandie](https://www.tamtam.ai/c/cerfrance-seine-normandie) (seine-normandie.cerfrance.fr)<br>With 29 agencies in Normandy and part of Île-de-France, Cerfrance Seine Normandie supports businesses with long-term success through project management and performance monitoring Explore job opportunities | Business Consulting and Services | 🇫🇷 Bois-Guillaume | 461 | 1956 |
| 35 | [Fondation Les Nids](https://www.tamtam.ai/c/fondation-les-nids) (lesnids.fr)<br>A reputable foundation in Normandy provides protection, support, education, and understanding to children and adolescents in need through various social services | Community Services | 🇫🇷 Mont-Saint-Aignan | 446 | 1931 |
| 36 | [Junior Senior](https://www.tamtam.ai/c/junior-senior) (juniorsenior.fr)<br>Junior Senior is a network of approved home care services providing various services like cleaning, gardening, childcare, and support for dependency and disability | Individual and Family Services | 🇫🇷 Le Havre | 427 | 1998 |
| 37 | [NATUP](https://www.tamtam.ai/c/natup) (natup.coop)<br>This agricultural and agri-food cooperative supports 7000 farmers, focusing on sustainable agriculture, processing, and distributing raw or transformed products across a wide territory. | Farming | 🇫🇷 Bois-Guillaume | 426 |  |
| 38 | [OXYPHARM](https://www.tamtam.ai/c/oxypharm) (vitadomia.com)<br>Oxypharm offers personalized medical technology solutions through collaboration with pharmacists, specializing in home medical equipment, respiratory care, infusion/nutrition/diabetes, and disability support | Home Health Care Services | 🇫🇷 Rouen | 425 |  |
| 39 | [Novacel](https://www.tamtam.ai/c/novacel) (novacel-solutions.com)<br>Provides technical films, tapes, papers, and machines to protect and preserve material surfaces across various industrial market segments. | International Trade and Development | 🇫🇷 Déville-lès-Rouen | 390 |  |
| 40 | [UbiPharm Group](https://www.tamtam.ai/c/ubipharm-group) (ubipharm.com)<br>UbiPharm enhances access to healthcare solutions in over 15 African countries by integrating key supply chain services with innovative distribution strategies | Wholesale | 🇫🇷 Le Grand-Quevilly | 386 | 1991 |
| 41 | [ENSM, École Nationale Supérieure Maritime](https://www.tamtam.ai/c/ensm-ecole-nationale-superieure-maritime) (supmaritime.fr)<br>Educates Merchant Navy Officers and Marine Engineers, covering navigation, maritime operations, and safety, with practical experience through internships and partnerships. | Higher Education | 🇫🇷 Le Havre | 381 | 1571 |
| 42 | [Aspen Notre-Dame-de-Bondeville](https://www.tamtam.ai/c/aspen-notre-dame-de-bondeville) (aspenndb.com)<br>Manufacturing sterile pharmaceutical products, including antithrombotics and injectable anesthetics, from active ingredient to finished product, with global distribution and ethical practices. | Pharmaceutical Manufacturing | 🇫🇷 Notre-Dame-de-Bondeville | 377 |  |
| 43 | [PGS GROUP](https://www.tamtam.ai/c/pgs-group) (pgsgroup.com)<br>Development and supply of customized wooden packaging solutions, including pallets and eco-friendly services, focused on cost-saving and sustainability. | Packaging and Containers Manufacturing | 🇫🇷 Saint-Étienne-du-Rouvray | 354 | 1993 |
| 44 | [NETMAN](https://www.tamtam.ai/c/netman) (netman.fr)<br>A family-owned company specialized in cleaning and logistics for sensitive industries, with 43 years of experience and a focus on safety and quality | Consumer Services | 🇫🇷 Valliquerville | 353 | 1977 |
| 45 | [Interior's](https://www.tamtam.ai/c/interior-s) (interiors.fr)<br>A French-based company specializing in unique furniture and accessories, handcrafted with traditional methods and exceptional quality wood, reflecting French 'Art de vivre' | Retail | 🇫🇷 Le Havre | 347 | 1977 |
| 46 | [ESIGELEC : ÉCOLE D'INGÉNIEURS-ES GÉNÉRALISTES](https://www.tamtam.ai/c/esigelec-ecole-d-ingenieurs-es-generalistes) (esigelec.fr)<br>Specializing in general engineering education, the company offers various programs in Intelligent and Connected Systems, emphasizing project-based learning, internships, entrepreneurship, and innovation for over 10,000 graduates | Higher Education | 🇫🇷 Saint-Étienne-du-Rouvray | 341 |  |
| 47 | [Écurie](https://www.tamtam.ai/c/ecurie) (ecur.ie)<br>A music label founded by Petit Biscuit to support new artists by providing guidance and opportunities without restrictive contracts Opening doors for emerging talent | Entertainment Providers | 🇫🇷 Rouen | 340 |  |
| 48 | [Mon Véto](https://www.tamtam.ai/c/mon-veto) (veterinaire-monveto.com)<br>Established in 2010 by veterinarians, this network of general veterinary clinics has expanded across various regions in France, boasting over 250 clinics and nearly 1900 veterinary professionals | Veterinary Services | 🇫🇷 Rouen | 335 | 2010 |
| 49 | [Alpha Maintenance](https://www.tamtam.ai/c/alpha-maintenance) (alpha.fr)<br>Company specializing in oil and energy sector, providing services and solutions based in Port-de-Bouc, France. | Engineering Services | 🇫🇷 Rouen | 333 | 1986 |
| 50 | [CORIA](https://www.tamtam.ai/c/coria) (coria.fr)<br>Focused on fundamental research and diagnostic development, primarily optical. Also models reactive flows and engages in laser physics. | Research Services | 🇫🇷 Saint-Étienne-du-Rouvray | 314 | 1967 |
| 51 | [Groupe SOGESTRAN](https://www.tamtam.ai/c/groupe-sogestran) (sogestran.com)<br>Inland waterway and maritime shipowner offering environmentally friendly transport for oil, chemicals, dry bulk, general goods, with focus on quality and safety | Maritime Transportation | 🇫🇷 Le Havre | 303 | 1948 |
| 52 | [Centre hospitalier intercommunal Elbeuf Louviers Val de Reuil](https://www.tamtam.ai/c/centre-hospitalier-intercommunal-elbeuf-louviers-val-de-reuil) (chi-elbeuf-louviers.fr)<br>Public healthcare facility in Normandy with 1083 beds, 2143 staff including 267 medical personnel, two hospital sites, maternity, and five nursing homes. | Hospitals and Health Care | 🇫🇷 Saint-Aubin-lès-Elbeuf | 291 | 1989 |
| 53 | [Greta Rouen Maritime](https://www.tamtam.ai/c/greta-rouen-maritime) (greta.ac-normandie.fr)<br>A company providing a wide range of vocational training programs through a network of 250 centers, offering over 280 courses to 2000+ individuals annually | Professional Training and Coaching | 🇫🇷 Mont-Saint-Aignan | 286 | 1974 |
| 54 | [LVO Group](https://www.tamtam.ai/c/lvo-group) (lv-overseas.fr)<br>Global logistics provider with presence in France, French overseas territories, Asia, Africa, Middle East, and US, offering flexible transport solutions worldwide | Transportation, Logistics, Supply Chain and Storage | 🇫🇷 Épouville | 281 | 1932 |
| 55 | [Transdev Rouen (TCAR)](https://www.tamtam.ai/c/transdev-rouen-tcar) (transdev.com)<br>Providing safe, efficient, and innovative mobility solutions for residents of the Rouen Normandy Metropolis to navigate the area | Urban Transit Services | 🇫🇷 Rouen | 274 |  |
| 56 | [Clinique Saint Hilaire](https://www.tamtam.ai/c/clinique-saint-hilaire) (clinique-sainthilaire.fr)<br>Medical surgical facility with 223 beds, 380 staff, 75 practitioners, offering innovative care across surgical, cardiovascular, and oncology specialties. | Hospitals and Health Care | 🇫🇷 Rouen | 265 | 1886 |
| 57 | [Atlas sécurité Privée](https://www.tamtam.ai/c/atlas-securite-privee) (atlas-securite.fr)<br>Specializes in providing security services across various sectors including public, events, retail, industry, nuclear, port, logistics, and tertiary. | Security and Investigations | 🇫🇷 Isneauville | 248 | 2003 |
| 58 | [Logeo Seine](https://www.tamtam.ai/c/logeo-seine) (logeo.fr)<br>Social housing company providing innovative residential solutions, enhanced customer service, and sustainable development for Normandy and Axe Seine territories. | Real Estate | 🇫🇷 Le Havre | 247 | 2016 |
| 59 | [GROUPE SEALOGIS](https://www.tamtam.ai/c/groupe-sealogis) (geodis.com)<br>Provides tailored maritime, inland, and air transport solutions with extensive European coverage and dedicated teams ensuring secure door-to-door delivery. | Maritime Transportation | 🇫🇷 Le Havre | 247 | 2002 |
| 60 | [Groupe Nutriset](https://www.tamtam.ai/c/groupe-nutriset) (groupenutriset.fr)<br>Research, production, and distribution of nutritional products to treat and prevent malnutrition among vulnerable populations worldwide. | Food and Beverage Manufacturing | 🇫🇷 Malaunay | 246 | 1986 |
| 61 | [Transdev Normandie](https://www.tamtam.ai/c/transdev-normandie) (transdev.com)<br>Providing sustainable, innovative, and secure mobility solutions for communities, Transdev Normandie collaborates with local authorities and businesses to optimize transportation services | Urban Transit Services | 🇫🇷 Sotteville-lès-Rouen | 243 | 2007 |
| 62 | [AVENEL SAS](https://www.tamtam.ai/c/avenel-sas) (avenel.fr)<br>A family-owned company founded in 1944 offering services in construction, industrial expertise, infrastructure projects, energy, and maintenance solutions | Construction | 🇫🇷 Darnétal | 242 | 1944 |
| 63 | [Réseau Alliance France](https://www.tamtam.ai/c/reseau-alliance-france) (recrutement.reseaualliance.fr)<br>The Alliance Network is a global HR solutions provider, supporting individuals throughout their careers by establishing trust with international companies in various industries | Staffing and Recruiting | 🇫🇷 Belbeuf | 238 | 2000 |
| 64 | [Notaire Test](https://www.tamtam.ai/c/notaire-test)<br>The company provides a range of services and solutions, with a focus on innovation and customer satisfaction | Legal Services | 🇫🇷 Rouen | 236 |  |
| 65 | [Voxens](https://www.tamtam.ai/c/voxens) (voxens.fr)<br>Manages multichannel call center operations for telephone marketing, focusing on customer acquisition, loyalty, retention, and reactivation for both B2B and B2C clients. | Outsourcing and Offshoring Consulting | 🇫🇷 Rouen | 227 | 2009 |
| 66 | [UGECAM NORMANDIE](https://www.tamtam.ai/c/ugecam-normandie) (groupe-ugecam.fr)<br>A non-profit group in France providing healthcare and support services for people with physical and intellectual disabilities, with a focus on equality and quality care | Hospitals and Health Care | 🇫🇷 Le Petit-Quevilly | 224 | 2000 |
| 67 | [VYV 3 Normandie](https://www.tamtam.ai/c/vyv-3-normandie) (normandie.vyv3.fr)<br>Provides extensive medical and paramedical care, social support services, and community health programs across Normandy for diverse populations. | Hospitals and Health Care | 🇫🇷 Rouen | 222 | 2014 |
| 68 | [Caux Seine agglo](https://www.tamtam.ai/c/caux-seine-agglo) (cauxseine.fr)<br>Caux Seine agglo is an intermunicipal cooperation organization uniting 50 municipalities and 77,777 residents, promoting economic and social development in the region | Public Policy Offices | 🇫🇷 Lillebonne | 212 | 2008 |
| 69 | [HOPITAL PRIVE DE L'ESTUAIRE](https://www.tamtam.ai/c/hopital-prive-de-l-estuaire) (hopital-prive-de-l-estuaire-le-havre.ramsaysante.fr)<br>A healthcare facility in Le Havre, part of Ramsay Santé group, providing comprehensive inpatient and outpatient services with a focus on high-quality patient care | Hospitals and Health Care | 🇫🇷 Le Havre | 212 | 2010 |
| 70 | [Les Ateliers du Goût](https://www.tamtam.ai/c/les-ateliers-du-gout) (les-ateliers-du-gout.fr)<br>Production of homemade-style French recipes for professional restaurateurs, emphasizing quality, teamwork, and regional manufacturing workshops. | Food and Beverage Manufacturing | 🇫🇷 Dieppe | 212 | 2018 |
| 71 | [IVT Security](https://www.tamtam.ai/c/ivt-security) (barkene.fr)<br>Design, installation, and maintenance of fire detection, intrusion alarms, video surveillance, access control, safes, and armored partitions for professional clients nationwide. | Security and Investigations | 🇫🇷 Yainville | 211 | 1986 |
| 72 | [Pressalit](https://www.tamtam.ai/c/pressalit) (pressalit.com)<br>A Danish company producing high-quality toilet seats, accessible bathrooms, and height-adjustable kitchens for people with reduced mobility since 1954 | Plastics Manufacturing | 🇫🇷 Ry | 211 | 1954 |
| 73 | [Havre Athletic Club](https://www.tamtam.ai/c/havre-athletic-club) (hac-foot.com)<br>French football club competing in Ligue 1, renowned for youth training, community engagement, stadium management, and business networking. | Spectator Sports | 🇫🇷 Le Havre | 210 | 1872 |
| 74 | [La MAE](https://www.tamtam.ai/c/la-mae) (mae.fr)<br>Specialist in child and family insurance, offering comprehensive protection solutions for accidents, home, and life stages with solidarity. | Insurance | 🇫🇷 Rouen | 210 | 1932 |
| 75 | [COIFF'IDIS](https://www.tamtam.ai/c/coiff-idis) (linktr.ee)<br>A leading provider of professional hairdressing and beauty products in France, founded in 1998, with a dedicated team of 245 employees supporting the industry | Wholesale | 🇫🇷 Darnétal | 208 | 1998 |
| 76 | [Ville de Sotteville-lès-Rouen](https://www.tamtam.ai/c/ville-de-sotteville-les-rouen) (sotteville-les-rouen.fr)<br>Local government promoting environmental sustainability, community participation, economic development, and quality of life through active urban planning and social initiatives. | Government Administration | 🇫🇷 Sotteville-lès-Rouen | 206 |  |
| 77 | [Paris Normandie](https://www.tamtam.ai/c/paris-normandie) (paris-normandie.fr)<br>Daily newspaper providing local news, sports, photos, and videos primarily in Haute-Normandie, serving as a regional media reference. | Newspaper Publishing | 🇫🇷 Rouen | 206 | 1944 |
| 78 | [SI2P](https://www.tamtam.ai/c/si2p) (centre-formation-securite.fr)<br>Si2p is a national training organization specializing in assisting businesses with workplace safety, offering fire safety and health at work training, audits, and equipment maintenance services | Professional Training and Coaching | 🇫🇷 Rouen | 202 | 2001 |
| 79 | [Nexira](https://www.tamtam.ai/c/nexira) (nexira.com)<br>Family-owned company, world leader acacia gum, global leader natural ingredients, botanical extracts, food, nutrition, dietary supplements, clean label. | Food and Beverage Manufacturing | 🇫🇷 Rouen | 200 | 1895 |
| 80 | [Alcéane](https://www.tamtam.ai/c/alceane) (alceane.fr)<br>Manage over 15,000 social housing units across 17 municipalities, housing 32,000 tenants, focusing on construction, rehabilitation, and social cohesion. | Real Estate | 🇫🇷 Le Havre | 200 |  |
| 81 | [Abysse Corp Group](https://www.tamtam.ai/c/abysse-corp-group) (abyssecorp.com)<br>Design, manufacture, and distribute licensed pop culture merchandise including manga, cinema, video games, with global offices and multiple product lines. | Wholesale | 🇫🇷 Grand Couronne | 192 | 2003 |
| 82 | [SIEMO](https://www.tamtam.ai/c/siemo) (siemo-france.com)<br>A family-owned company specializing in insulation, scaffolding, and fireproofing for industrial sites, focusing on safety, environment, and client satisfaction | Construction | 🇫🇷 Lillebonne | 191 | 1990 |
| 83 | [Sogea Nord-Ouest](https://www.tamtam.ai/c/sogea-nord-ouest) (france.vinci-construction.com)<br>A major construction player in Normandy, offering a wide range of building services from design to maintenance, tailored solutions for functional, residential, and industrial projects | Construction | 🇫🇷 Rouen | 191 |  |
| 84 | [SOCAPS](https://www.tamtam.ai/c/socaps) (socaps.coop)<br>Global leader in technical assistance and consulting services for various industries worldwide, focusing on skills development, ecological transition, and societal innovations | Engineering Services | 🇫🇷 Rouen | 189 | 1999 |
| 85 | [Bulle de Linge](https://www.tamtam.ai/c/bulle-de-linge) (bulledelinge.com)<br>Specializing in laundry services for residents, providing quality clothing care for over 60,000 individuals in 800 facilities, promoting well-being for dependent individuals | Laundry and Drycleaning Services | 🇫🇷 Saint-Martin-du-Vivier | 186 | 2007 |
| 86 | [CLINIQUE DU CEDRE](https://www.tamtam.ai/c/clinique-du-cedre) (clinique-du-cedre.fr)<br>A hospital and health care company located in Bois Guillaume, France, specializing in providing medical services to patients | Hospitals and Health Care | 🇫🇷 Bois-Guillaume | 184 |  |
| 87 | [Aris Services](https://www.tamtam.ai/c/aris-services) (aris-services.com)<br>Specializes in thermal insulation, scaffolding, and asbestos removal with extensive experience serving maritime, nuclear, and industrial sectors across France. | Manufacturing | 🇫🇷 Épouville | 183 |  |
| 88 | [Nachos Mexican Good Food](https://www.tamtam.ai/c/nachos-mexican-good-food) (nachos.fr)<br>Fast-casual Mexican restaurants, fresh, tasty, and healthy food prepared on-site. Expanding through franchising across France, offering a recognized franchise network. | Restaurants | 🇫🇷 Rouen | 182 | 2013 |
| 89 | [Segafredo Zanetti France S.A.S.](https://www.tamtam.ai/c/segafredo-zanetti-france-s-a-s) (segafredo.fr)<br>Specializes in coffee roasting, packaging, and marketing, focusing on product quality, customer satisfaction, innovation, and corporate social responsibility. | Food and Beverage Manufacturing | 🇫🇷 Sotteville-lès-Rouen | 180 | 1991 |
| 90 | [SLAUR SARDET](https://www.tamtam.ai/c/slaur-sardet) (slaur.com)<br>A leading French manufacturer of alcoholic beverages, syrups, and private label products, known for excellence, innovation, and global export | Beverage Manufacturing | 🇫🇷 Le Havre | 180 | 1972 |
| 91 | [Préfecture de la région Normandie et de la Seine-Maritime](https://www.tamtam.ai/c/prefecture-de-la-region-normandie-et-de-la-seine-maritime) (seine-maritime.gouv.fr)<br>Official account providing government services and information for the Normandy region and Seine-Maritime department, including social media moderation guidelines. | Government Administration | 🇫🇷 Rouen | 180 |  |
| 92 | [Bâtiment CFA Normandie](https://www.tamtam.ai/c/batiment-cfa-normandie) (batimentcfanormandie.fr)<br>The company offers diverse training in the construction industry, emphasizing energy and digital transitions, apprenticeships, and the opportunity for young individuals to explore various trades before specializing | Professional Training and Coaching | 🇫🇷 Saint-Étienne-du-Rouvray | 174 | 2018 |
| 93 | [Matmut Protection Juridique](https://www.tamtam.ai/c/matmut-protection-juridique) (matmut.fr)<br>Offering Legal Protection guarantees for individuals and professionals as a subsidiary of the Matmut Group Stay updated on the Group and its subsidiaries on their LinkedIn page! | Legal Services | 🇫🇷 Rouen | 173 |  |
| 94 | [AE Partner](https://www.tamtam.ai/c/ae-partner) (aepartner.dk)<br>Specializing in designing and producing complex automation systems and electrical panels, offering consultations, custom designs, and a focus on quality and customer satisfaction | Automation Machinery Manufacturing | 🇫🇷 Ry | 172 | 1996 |
| 95 | [Ligue Havraise, pour l'aide aux personnes handicapées](https://www.tamtam.ai/c/ligue-havraise-pour-l-aide-aux-personnes-handicapees) (liguehavraise.fr)<br>A non-profit association founded in 1958, supporting individuals with intellectual, psychiatric, autism, or multiple disabilities to defend their interests and rights | Civic and Social Organizations | 🇫🇷 Le Havre | 172 | 1958 |
| 96 | [ADEP](https://www.tamtam.ai/c/adep) (adep.eu)<br>An organization that runs social inclusion workshops, professional training in personal services, and an intermediary association for job insertion | Civic and Social Organizations | 🇫🇷 Rouen | 172 | 2008 |
| 97 | [SOGET](https://www.tamtam.ai/c/soget) (soget.fr)<br>A global leader in Port Community Systems, offering e-Customs solutions, Warehouse Management, and container tracking services to streamline port operations worldwide | IT Services and IT Consulting | 🇫🇷 Le Havre | 171 | 1983 |
| 98 | [IUT de Rouen](https://www.tamtam.ai/c/iut-de-rouen) (iutrouen.univ-rouen.fr)<br>The company offers a variety of technical and professional training programs at the university level, focusing on specialized fields and emphasizing practical skills for quick professional integration | Education Administration Programs | 🇫🇷 Mont-Saint-Aignan | 168 | 1966 |
| 99 | [LMH](https://www.tamtam.ai/c/lmh) (lm-h.fr)<br>It specializes in personalized architectural and decorative projects, ensuring high thermal performance products, functionality, and customer satisfaction through reliable partnerships. | Construction | 🇫🇷 Quincampoix | 167 | 2020 |
| 100 | [NORMANDIE MANUTENTION](https://www.tamtam.ai/c/normandie-manutention) (normandiemanutention.fr)<br>Supplier of business supplies and equipment based in Upper Normandy, providing essential tools and materials for various industries. | Wholesale Machinery | 🇫🇷 Saint-Étienne-du-Rouvray | 166 | 1979 |

## How this list is built

Every company on this list has a Tamtam company profile. The industry is the one the company gives on LinkedIn; categories such as SaaS or fintech are classified by Tamtam's AI from the company's website and LinkedIn page; and the headquarters city must match the company's own address. Companies are ranked by the number of employees on LinkedIn, and the list is refreshed every night. Classifications can be wrong, so treat the list as a starting point rather than an official ranking. Last updated Nov 11, 2026.

## More company lists in the Seine-Maritime department

- [Retail chains in the Seine-Maritime department](https://www.tamtam.ai/l/retail-chains-seine-maritime) (97)
- [Multinational companies in the Seine-Maritime department](https://www.tamtam.ai/l/multinational-companies-seine-maritime) (89)
- [Manufacturers in the Seine-Maritime department](https://www.tamtam.ai/l/manufacturers-seine-maritime) (72)
- [Companies with in-house R&D in the Seine-Maritime department](https://www.tamtam.ai/l/r-and-d-companies-seine-maritime) (67)
- [Public sector organisations in the Seine-Maritime department](https://www.tamtam.ai/l/public-sector-organisations-seine-maritime) (65)
- [Distributors and wholesalers in the Seine-Maritime department](https://www.tamtam.ai/l/distributors-and-wholesalers-seine-maritime) (53)
- [Professional services firms in the Seine-Maritime department](https://www.tamtam.ai/l/professional-services-firms-seine-maritime) (51)
- [Critical infrastructure operators in the Seine-Maritime department](https://www.tamtam.ai/l/critical-infrastructure-operators-seine-maritime) (46)
- [Family-owned companies in the Seine-Maritime department](https://www.tamtam.ai/l/family-owned-companies-seine-maritime) (44)
- [IT services companies in the Seine-Maritime department](https://www.tamtam.ai/l/it-services-companies-seine-maritime) (40)
- [Hardware manufacturers in the Seine-Maritime department](https://www.tamtam.ai/l/hardware-companies-seine-maritime) (38)
- [Education providers in the Seine-Maritime department](https://www.tamtam.ai/l/education-companies-seine-maritime) (36)
- [Healthcare providers in the Seine-Maritime department](https://www.tamtam.ai/l/healthcare-providers-seine-maritime) (34)
- [Logistics companies in the Seine-Maritime department](https://www.tamtam.ai/l/logistics-companies-seine-maritime) (34)
- [Financial services firms in the Seine-Maritime department](https://www.tamtam.ai/l/financial-services-firms-seine-maritime) (32)
- [IT Services and IT Consulting companies in the Seine-Maritime department](https://www.tamtam.ai/l/it-services-and-it-consulting-companies-seine-maritime) (30)
- [Real Estate companies in the Seine-Maritime department](https://www.tamtam.ai/l/real-estate-companies-seine-maritime) (30)
- [Higher Education companies in the Seine-Maritime department](https://www.tamtam.ai/l/higher-education-companies-seine-maritime) (28)
- [Software Development companies in the Seine-Maritime department](https://www.tamtam.ai/l/software-development-companies-seine-maritime) (28)
- [Government Administration companies in the Seine-Maritime department](https://www.tamtam.ai/l/government-administration-companies-seine-maritime) (27)
- [Industrial Machinery Manufacturing companies in the Seine-Maritime department](https://www.tamtam.ai/l/industrial-machinery-manufacturing-companies-seine-maritime) (27)
- [Consulting firms in the Seine-Maritime department](https://www.tamtam.ai/l/consulting-firms-seine-maritime) (26)
- [Hospitals and Health Care companies in the Seine-Maritime department](https://www.tamtam.ai/l/hospitals-and-health-care-companies-seine-maritime) (25)

## The same list elsewhere in France

- [The largest companies in France](https://www.tamtam.ai/l/largest-companies-france) (90,813)
- [The largest companies in Île-de-France](https://www.tamtam.ai/l/largest-companies-ile-de-france) (36,143)
- [The largest companies in Auvergne-Rhône-Alpes](https://www.tamtam.ai/l/largest-companies-auvergne-rhone-alpes) (11,033)
- [The largest companies in Provence-Alpes-Côte d'Azur](https://www.tamtam.ai/l/largest-companies-provence-alpes-cote-dazur) (6,699)
- [The largest companies in Occitanie](https://www.tamtam.ai/l/largest-companies-occitanie) (5,769)
- [The largest companies in Grand Est](https://www.tamtam.ai/l/largest-companies-grand-est) (5,700)
- [The largest companies in Nouvelle-Aquitaine](https://www.tamtam.ai/l/largest-companies-nouvelle-aquitaine) (5,460)
- [The largest companies in the Hauts-de-Seine department](https://www.tamtam.ai/l/largest-companies-hauts-de-seine) (5,160)
- [The largest companies in the Rhône department](https://www.tamtam.ai/l/largest-companies-rhone) (4,813)
- [The largest companies in Hauts-de-France](https://www.tamtam.ai/l/largest-companies-hauts-de-france) (4,505)
- [The largest companies in Pays de la Loire](https://www.tamtam.ai/l/largest-companies-pays-de-la-loire) (4,269)
- [The largest companies in the Bouches-du-Rhône department](https://www.tamtam.ai/l/largest-companies-bouches-du-rhone) (3,318)
- [The largest companies in Brittany](https://www.tamtam.ai/l/largest-companies-brittany) (3,058)
- [The largest companies in the Nord department](https://www.tamtam.ai/l/largest-companies-nord) (2,806)
- [The largest companies in the Gironde department](https://www.tamtam.ai/l/largest-companies-gironde) (2,435)
- [The largest companies in the Haute-Garonne department](https://www.tamtam.ai/l/largest-companies-haute-garonne) (2,406)
- [The largest companies in Normandy](https://www.tamtam.ai/l/largest-companies-normandy) (2,380)
- [The largest companies in the Loire-Atlantique department](https://www.tamtam.ai/l/largest-companies-loire-atlantique) (2,046)
- [The largest companies in Bourgogne-Franche-Comté](https://www.tamtam.ai/l/largest-companies-bourgogne-franche-comte) (1,867)
- [The largest companies in Centre-Val de Loire](https://www.tamtam.ai/l/largest-companies-centre-val-de-loire) (1,701)
- [The largest companies in the Alpes-Maritimes department](https://www.tamtam.ai/l/largest-companies-alpes-maritimes) (1,538)
- [The largest companies in Paris](https://www.tamtam.ai/l/largest-companies-paris) (22,790)
- [The largest companies in Lyon](https://www.tamtam.ai/l/largest-companies-lyon) (2,679)
- [The largest companies in Toulouse](https://www.tamtam.ai/l/largest-companies-toulouse) (1,565)

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Source: https://www.tamtam.ai/l/largest-companies-seine-maritime